Behaviour of natural radionuclides in coal combustion

¹ Unit of Radiological Protection of the Public and Environment, CIEMAT, Avda. de la Complutense 22, 28040 Madrid, Spain
² Environmental Radioactivity Laboratory, University of Extremadura, Avda. de la Universidad SN, 10071 Cáceres, Spain

Abstract

The study presented here, being its main goal to evaluate the behaviour of natural radionuclides in coal combustion, is part of a wider study carried out by CIEMAT and the University of Extremadura (UEX). The research is addressed to the radiological evaluation of the workers and the public as a result of the operation of the four biggest Spanish Coal-Fired Power Plants (CFPPs). Some generally used effects were confirmed in this study, as the difference in concentration of ²¹⁰Po in fly and bottom-ashes. Enrichment factors relative to ⁴⁰K as defined by UNSCEAR were found to be a little different than expected. ²¹⁰Po enrichment was found in gypsum (material obtained as a by-product in the desulphuration process). In order to confirm the assumption considered to explain difference in ²³²Th activity concentration between bottom and fly ashes, carbon content was measured, obtaining that it should be reviewed.